001/* 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017package org.apache.camel.util.concurrent; 018 019import java.util.List; 020import java.util.concurrent.AbstractExecutorService; 021import java.util.concurrent.TimeUnit; 022 023/** 024 * A synchronous {@link java.util.concurrent.ExecutorService} which always invokes the task in the caller thread (just a 025 * thread pool facade). 026 * <p/> 027 * There is no task queue, and no thread pool. The task will thus always be executed by the caller thread in a fully 028 * synchronous method invocation. 029 * <p/> 030 * This implementation is very simple and does not support waiting for tasks to complete during shutdown. 031 */ 032public class SynchronousExecutorService extends AbstractExecutorService { 033 034 private volatile boolean shutdown; 035 036 @Override 037 public void shutdown() { 038 shutdown = true; 039 } 040 041 @Override 042 public List<Runnable> shutdownNow() { 043 // not implemented 044 return null; 045 } 046 047 @Override 048 public boolean isShutdown() { 049 return shutdown; 050 } 051 052 @Override 053 public boolean isTerminated() { 054 return shutdown; 055 } 056 057 @Override 058 public boolean awaitTermination(long time, TimeUnit unit) throws InterruptedException { 059 // not implemented 060 return true; 061 } 062 063 @Override 064 public void execute(Runnable runnable) { 065 // run the task synchronously 066 runnable.run(); 067 } 068 069}